Vesicular stomatitis virus RNA synthesis will be studied in a variety of ways. Temperature-sensitive mutants will be characterized phenotypically and biochemically for their apparent temperature-sensitive lesions. Fine mapping of these mutants will be by RNA heteroduplex formation between mesenger RNA and virion RNA. Regions of virus-specific RNA's will be sequenced. In vitro reconstruction of RNA and proteins will be attempted in order to see what functions are provided by which polypeptides during the polymerase reaction and subsequent processing of messenger RNA. These studies will be extended to defective interfering particles and the RNA's whenever applicable. Biological studies will focus on the in vitro persistent infections. The effects of temperature antibody and age on the production of defective interfering particles will be examined. BIBLIOGRAPHIC REFERENCE: Huang, A.S. (1975) Ribonucleic Acid synthesis of vesicular stomatitis virus in Negative Stranded Viruses, Vol. 1, ed. B. W. J. Mahy and R. D. Barry, Academic Press, N. Y., pp 353-359.